We can't get too excited about an adapter, but Belkin's AV360, a device that bridges the gap between a 27-inch iMac and your HDMI-based video components, has stirred our enthusiasm by meaningfully differentiating itself from its competition. The key trick of the Belkin AV360 lies in its ease-of-use. It requires less fiddling than the competing Kanex XD. It also plays better with HDMI switchers, a task that gave the Kanex model trouble. Throw in the fact that the Belkin AV360 and the Kanex XD each have a list price of $150 and our decision is easy. If you own a 27-inch iMac, and you want to pump in your cable box, your game console, or a Blu-ray player into the Mini DisplayPort input, the Belkin AV360 is the best device for the job.
We concede that these adapters will only appeal to a limited audience. Technically, they work with any display that has a Mini DisplayPort input, but their primary reason for being is to input home video components into the 27-inch iMac. It would have been far more convenient had Apple built an HDMI input into its largest iMac from the start. Perhaps the recent addition of HDMI to the Mac Mini offers hope for the next iMac update. For now, annoyingly, you'll need a specialized Mini DisplayPort-to-HDMI adapter that can convert an input signal. A standard, inexpensive Mini DisplayPort-to-HDMI output adapter won't do the job.
The Belkin AV360 is actually significantly larger than the Kanex XD. The Belkin model measures 0.875 inch high, 6.25 inches wide, and 3.375 inches deep. That's nearly three times the width of the Kanex XD. We suspect the Belkin's extra size has to do with extra internal components that provide important differences between the two adapters.
The first difference is that unlike the Kanex XD and its wall-wart power adapter, the Belkin AV360 is USB-powered. That's a minor distinction, as wall outlets are as easy to replicate as USB ports, but in the interest of minimizing cable clutter, we prefer the AV360. It keeps your desk tidier by routing the adapter's cables in only two directions, as opposed to three with the Kanex XD. The bigger advantage for the Belkin AV360 is that it simplifies the configuration steps due to its built-in resolution scaling.
The resolution scaling is important due to the limits of the iMac, which Apple only configured to handle certain resolutions through its Mini DisplayPort input. It will accept video sources in its native 2,560x1,440 pixel resolution, but it's not equipped to handle 1,920x1,080, aka 1080p. Instead, the next highest resolution is 1,280x720, or 720p.
With the Kanex XD, that resolution limitation means you need to preset your video source to 720p, which potentially requires you to connect the device to another display first to lower the output resolution. Thanks to its scaler, the Belkin AV360 requires no such intermediate step. You can simply connect an external HDMI video source and the AV360 will automatically adjust the output to iMac-friendly 720p.
We can also report that the Belkin AV360 actually surpasses the Kanex XD in terms of its compatibility. Like the Kanex, the AV360 worked flawlessly with a cable box, with a PlayStation 3, and an Xbox 360 Slim. The AV360 also worked well with a Blu-ray player.
While we didn't subject it to a formal image quality test (if you're serious about Blu-ray image quality, you should be looking for a true HDTV instead of going through an iMac adapter), but casually speaking we'd say the AV360's Blu-ray image quality looked better than that of the Kanex XD. The AV360's image was crisp, while the Kanex XD seemed to lose some clarity.
We were also happy to find that the AV360 had no trouble resolving a signal from a cable box through an HDMI switcher. The Kanex XD couldn't do that. Anyone hoping to route their entire home entertainment suite through their iMac would want to use a switcher to avoid having to swap HDMI inputs. The AV360 makes that seamless, whereas the Kanex XD fails.
We went a bit further in our testing of the AV360 than in our Kanex XD review, because it occurred to us that the HDMI adapter could provide an easy way to connect the new Mac Mini or an HDMI-equipped PC to the iMac. Sadly we weren't able to make that work with either device. The Mac Mini gave us just a blank screen with the AV360. It resolved the screen of a Windows 7-based desktop for a second or two, then went black and started churning out audio static. We then doubled back and tried the same systems on the Kanex XD, with similar results. Belkin says only that it might add PC support in a future firmware update.
We don't have an Apple Cinema Display to test with the AV360, but Belkin says the AV360 will work with that display as well, and at resolutions up to 1,920 x 1,080. The AV360 will not, however, support the 27-inch iMac's native 2,550x1,440 resolution. Kanex says the Kanex XD will actually go that high. Aside from computers, which neither the AV360 nor the Kanex XD support, we can't think of many other HDMI-equipped devices that can output at such a high resolution, so we're not sure we really miss that support in the AV360. Perhaps there's a professional-quality HD camcorder or camera out there that could use it, but we suspect most consumer-oriented owners of a 27-inch iMac would happily trade 2,550x1,440 support for the ease with which the AV360 translates 1080p to 720p content on the iMac.